【摘要】 以不同年份铁皮石斛(Dendrobium officinale Kimura et Migo)的茎为材料,对其进行多糖、单糖以及木质素含量的测定以及多元线性回归分析,同时对铁皮石斛的茎进行番红-固绿和Mule染色,并利用FTIR、1H-NMR技术对铁皮石斛茎中木质素单体的类型进行鉴定。结果显示,铁皮石斛茎木质素的积累与葡萄糖含量呈显著正相关,与多糖含量、甘露糖含量及甘露糖和葡萄糖的比值呈显著负相关,说明木质素的沉积对多糖的积累有一定影响。铁皮石斛茎维管束的木质部和鞘均含有木质素。随着年份的增加,铁皮石斛茎的维管束鞘厚壁细胞厚度增加,维管束鞘的发达程度增大。Mule染色及FTIR和1H-NMR分析结果显示,铁皮石斛的茎主要含有愈创木基型(G型)和紫丁香基型(S型)木质素,同时含有微量的对羟基苯基型(H型)木质素。G型木质素主要分布在维管束的木质部,S型木质素主要分布在维管束鞘厚壁细胞中。铁皮石斛茎S/G比值随年份增加呈上升趋势。更多还原

【Abstract】 The stems of Dendrobium officinale Kimura et Migo in different years were used as study materials. The contents of polysaccharides, monosaccharides, and lignin were determined,and the relationships among them were analyzed by multiple linear regression analysis. The D. officinale stems were stained using saffron,fast green,and Mule staining,and the lignin monomer types were determined by Fourier transform infrared( FTIR) and proton nuclear magnetic resonance(~1H-NMR) spectroscopy. As a result,lignin accumulation was significantly positively correlated with glucose content, and significantly negatively correlated with polysaccharide and mannose content and the mannose to glucose ratio. These results suggested that the accumulation of polysaccharides was influenced by the deposition of lignin. The xylem and sheath of the vascular bundles in the D. officinale stems contained lignin.With the increase in years,the thickness of the vascular thick-walled cells in the D. officinale stems increased,and the degree of development of the vascular bundle sheaths increased.Mule staining and FTIR and ~1H-NMR spectrometry showed that the stems of D. officinale mainly contained guaiacyl lignins( G lignins) and syringyl lignins( S lignins),as well as trace hydroxyl-phenyl lignins( H lignins). G lignins were mainly distributed in the xylem,while S lignins were mainly distributed in the thick-walled cells. The S/G ratio in the D. officinale stems showed an upward trend with increasing years.更多还原